21702493 has 8 divisors (see below), whose sum is σ = 22208256. Its totient is φ = 21200400.

The previous prime is 21702491. The next prime is 21702517. The reversal of 21702493 is 39420712.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21702493 - 2¹ = 21702491 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21702491) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 13608 + ... + 15118.

It is an arithmetic number, because the mean of its divisors is an integer number (2776032).

Almost surely, 2^21702493 is an apocalyptic number.

It is an amenable number.

21702493 is a deficient number, since it is larger than the sum of its proper divisors (505763).

21702493 is a wasteful number, since it uses less digits than its factorization.

21702493 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1835.

The product of its (nonzero) digits is 3024, while the sum is 28.

The square root of 21702493 is about 4658.5934572572. The cubic root of 21702493 is about 278.9351262088.

The spelling of 21702493 in words is "twenty-one million, seven hundred two thousand, four hundred ninety-three".